Gardeners, landscapers and homeowners frequently use border or edging material such as fences, logs, railroad ties, bricks, concrete blocks and the like to provide a decorative edge for a landscape or garden. Such border or edging material is also frequently employed to physically separate landscape, garden and other areas from one another.
Plastic landscape edging is now commonly used to divide and separate different landscape areas to preclude material in one area from spilling over into an adjacent area, and to prevent grass, flowers or the like contained in one area from growing in an adjoining area. For example, plastic edging is typically used to divide grass landscape areas from adjoining garden areas, and helps prevent grass from taking root in adjoining garden areas. Plastic edging also helps prevent garden bedding material from spilling onto the adjoining landscape area. The most prevalent materials used to fabricate landscape edging today are inert, synthetic flexible plastics such as polyethylene and ethylene vinyl acetate.
In the past, landscape edging has been formed from lengths of wood, corrugated metal strips, plastic, cement blocks and poured concrete. Wood is subject to rot and insect attack and decays over time. Wood landscape timbers must therefore be replaced rather frequently. Ungalvanized metal bands oxidize and rust, and tend to become bent and misshapen over time. Even galvanized metal bands eventually corrode once the protective zinc coating has been oxidized. Concrete blocks are inflexible, difficult to install and generally heavy. Poured concrete is expensive, difficult or impossible to modify once poured and set, and difficult and time-consuming to install.
Plastic landscape edging, on the other hand, is inexpensive, readily manufactured, flexible and has a long service life. As a result of the disadvantages inhering in wood, metal and concrete landscaping materials and the unique advantages of plastic, plastic landscape edging has become the landscape edging material of choice of many consumers.
While landscape edging formed from inert synthetic plastic has many advantages such as being flexible and resisting deterioration well, problems nevertheless occur in their use. Conventional landscape edging usually consists of a longitudinally extending strip of material having a lower edge that is inserted into the ground to a predetermined depth and an upper edge or rail that generally projects above the ground. The edging is typically installed by digging a narrow trench, inserting the lower edge to a predetermined depth, refilling the trench and compacting the earth around the edging. Such installation normally maintains the edging in its intended position for a period of time.
As time progresses, however, the environment and other factors actively work against the edging remaining in its original position. The edging may be walked on, bumped, kicked, shoved aside or otherwise engaged in such a manner that it is displaced in respect of its original position. Landscape mowers or tractors may repeatedly drive over the edging and displace or damage the edging.
The winter effects of frost heave, or the freezing and thawing action of the earth surrounding the edging, are often more severe than the foregoing effects in respect of edging displacement or damage. The ground retains moisture in the fall that freezes with dropping temperatures. Water is one of the few materials having a coefficient of volume expansion that increases as temperature decreases, and the ground accordingly expands with frozen moisture in the winter. This has the effect of compressing and heaving the landscape edging, and as a result the edging breaks or is laterally or vertically displaced. When spring arrives in colder climates, plastic landscape edging is often found to have buckled upwards and protruded from the ground during the winter in response to frost heave, especially where adjacent strips of edging are connected to one another. As temperatures rise in spring, the moisture beneath the ground surface melts, again changing the volume of the subsurface ground adjoining the edging. As the seasons alternate, the landscape edging is repeatedly exposed to a variety of forces arising from changing soil volumes that, over the long term, cause the edging to become dislodged or damaged.
Landscape edging systems, components and methods are well known in the art, some examples of which may be found in the issued U.S. Patents listed in Table 1 below.
Table 1 ______________________________________ Prior Art Patents Patent Number Title ______________________________________ 425,890 Border for Flower Bed 1,166,664 Curbing Block 1,183,055 Dividing Stone for Gardens or Landscape s 1,843,108 Curb or Edging for garden Paths and the Like 1,977,021 Root Fence for Flower Edges and the Like 2,094,519 Walk and Drive Edging 2,235,356 Protective Tile for Covering Underground Cables 2,713,751 Garden Edging Device 2,744,357 Landscape Edging Device 2,746,723 Border Fencing 2,769,277 Terrace Barrier or Curbing 2,794,375 Sectional Curbs for Parking Lots and the Like 2,865,136 Border Block 2,920,184 Illuminated Driveway Curbing 3,289,349 Curbing and Bordering Means 3,387,786 Divider and Sprinkler Combination 3,636,829 Parking Barrier 4,074,479 Landscape Edging 4,281,473 Landscaping Bed Divider 4,601,140 Landscape Edging System 4,628,632 Edging Strip 4,644,685 Edging Strip 4,695,502 Interlocking Landscape Planking 4,702,034 Edging Assembly 4,747,231 Landscape Edging 4,761,923 Landscape Edging 4,809,459 Building and Garden Edging 4,823,521 Landscaping Bed Divider 4,897,973 Modular Sun Block System 4,945,675 Dividing, Watering and Lighting System for Landscape s 4,969,289 Garden Edging Device 5,027,551 Decorative Landscape Edging Package 5,067,273 Landscape Edging 5,080,523 Concrete Stone for Forming Road Edges 5,117,583 Landscape Terracing Material 5,119,587 Method and Apparatus for Landscape Edging 5,121,569 Landscape Edging Device 5,133,163 Conduit Containing Construction Block 5,154,399 Implement for Removing Landscape Edging 5,157,867 Landscape Edging Apparatus and Method 5,168,678 Modular Landscaping System and Structures 5,201,154 Landscape Edging and Methods of Manufacturing and Using Same 5,233,806 Articulating Stone Edging Construction 5,236,179 Garden Trim Fence 5,259,154 Landscape Border 5,315,780 Landscape Edging Material Anchoring Arrangement 5,317,833 Landscape and Flower Bed Edging 5,375,369 Landscape Edgings with Stakeable Connectors 5,377,447 Landscape Edging Apparatus and Method 5,410,458 Illuminated Landscape Edging 5,414,956 Interlocking Garden Edging and Ornament 5,421,118 Landscape Edging System 5,426,888 Landscape Edging System 5,438,804 Landscape Edging 5,442,877 Modular Landscape Borders 5,501,036 Even-Coil Edging for Cartonless Packaging 5,519,970 Landscape Edging 5,531,044 Landscape Edging Device and Method 5,535,568 Self Indexing Landscape Module 5,544,445 Landscape Edging Device 5,564,240 Edging Block and Method of Enclosing an Area Utilizing a Series of Edging Blocks Des. 335,429 Male End Cap for Landscaping Terracing Des. 363,801 Border Edge ______________________________________
Particular attention is directed to the following prior art patents: U.S. Pat. Nos. 3,762,113 to O'Mullen; 4,747,231 to LeMay et al.; 4,945,675 to Kendrick; 5,027,551 to Rodriguez; 5,119,587 to Waltz; 5,240,343 to Strobl, Jr.; and 5,421,118 to Bauer.
Those of skill in the art will appreciate readily upon reading the Summary of the Invention, Detailed Description of the Preferred Embodiments and Claims set forth below, that at least some of the devices and methods disclosed in the patents of Table 1 may be modified advantageously using the teachings of the present invention.